html{
    height: 100%;
}
body{
    margin: 0;
    padding: 0;
    font-size: 10px;
    background-color: #00a1e9;
}
*{
    box-sizing: border-box;
}
header{
    width: 100vw;
    height: 5rem;
    background-color: #87cefa;
    position: fixed;
    top: 0;
    left: 0;
}
main{
    width: 80vw;
    margin: 0 auto;
    height: 5rem;
    font-size: 1.6rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
main div{
    width: 3rem;
    height: 3rem;
    border-radius: 50%;
    background-image: url(../img/title.jpg);
    background-position: center center;
    background-size: 100% 100%;
}
main a{
    display: block;
    width: 10vw;
    height: 5rem;
    line-height: 5rem;
    text-align: center;
    color: #333;
    text-decoration: none;
    opacity: 0.8;
}
main a:hover{
    opacity: 1;
    background-color: #00a1e9;
}
.center{
    width: 80vw;
    margin: 0 auto;
    margin-top: 5rem;
    display: flex;
    justify-content: space-between;
}
.l a ,.c a{  
    display: block;
    text-decoration: none;
    width: 20vw;
    height: 5rem;
    line-height: 5rem;
    text-align: center;
    font-size: 1.6rem;
    color: #999;
    border-radius: 0.5rem;
    margin-top: 2rem;
}
.l a:hover{
    color: white;
}
.l a:nth-child(2n){
    background-color: LightPink;
}
.l a:nth-child(2n+1){
    background-color: LightGreen;
}
.c h2{
    width: 20vw;
    height: 5rem;
    line-height: 5rem;
    text-align: center;
    font-size: 1.6rem;
    margin: 0;
    margin-top: 2rem;
    color: white;
    border-radius: 0.5rem;
    background-color: lightcoral;
}
.c a{
    height: 3rem;
    line-height: 3rem;
    background-color: lemonchiffon;
}
.r a{
    display: block;
    width: 10vw;
    height: 3rem;
    line-height: 3rem;
    text-align: center;
    text-decoration: none;
    color: white;
    font-size: 1.2rem;
    background-color: #666;
    border-radius: 0.5rem;
    margin-top: 2rem;
}
footer{
    width: 100vw;
    height: 5rem;
    text-align: center;
    background-image: url(../img/bg.png);
    background-size: 30% 100%;
    background-position: left center;
    background-repeat: repeat-x;
    position: absolute;
    left: 0;
    bottom: 0;
}